Cylinder Misfires

Yes sir

 

I did mine myself...... Around $300............ but everything else also crapped out..... traction battery, bake pump and accumulator, water pump, inverter, and finally the trani................ I fixed everything..... really didn't save much gas money..... got a used matrix....and now don't worry about the for sure hybrid problems coming up. I need a car I can travel in and not wonder when a hybrid problem is going to happen.
I don't know why people on here think these cars will be reliable like a non hybrid toy... the evidence is on here almost daily...... great for first maybe 150,000 but after that roll of the dice.... I was 1100 miles from home one time.... was stranded for several weeks..............
Another junk toy head gasket................. and people still don't believe me........... I only post this in case potential buyer on here thinks of the great service they got out of their non hybrid toy.... it just ain't gonna happen. I like toys and have drove them several hundreds of thousands of miles with minimal problems until the gen 3.

 

Around Central Texas I could find the following options. Not at every shop by any means.

A head gasket job $1500 with new gaskets and nothing else. $2500 up with a rebuilt head and cleaned egr and intake. Most dealers and many independents won't do a gen3 head gasket because of the repeat failure risk. They also don't buy the clogged egr theory. They believe in bad rings, warped heads and occasional scored cylinders.

So the next set of options:
------

1. Straight junkyard used engine. No rebuild of anything, no new gaskets, no real guarantee. Generally the lowest cost. $1500-$2500 installed. Could break two weeks later, could be a severe oil burner, could be a disaster. But often tried, high risk, low cost.

2. A JDM used in Japan engine. Usually some guarantee, higher installed cost, maybe $2500-$3500.

3. A used engine with a partial teardown and inspection, reassembled with a machined head and new gaskets. Typically solves head gasket issues and oil leaks on the used engine if existing. Some guarantee. Maybe $3000-$3500.

4. A used engine with a complete rebuild including teardown, inspection, new rings, bearings, machined head but with existing accessories like water pumps. Often a decent warranty and best bet for 150,000 miles. Usually the dealer option. Sometimes a dealer will include a complete new short block (bottom end with pistons and rings) $3500-$7000.

5. Similar to #4, a complete rebuild by a professional engine shop shipped to your local mechanic for installation. Often better quality than a local shop attempting a rebuild. $3500-$5000.

Typically auxiliary parts are replaced as needed or if requested on top of any of these options. Water pumps, thermostats, intake manifolds, plugs etc if yours are carboned up or bad. Extra cost but usually definable upfront.

Pricing varies but a knowledgeable owner can shop and get real value. Dealers are often half again to twice the cost of better independents.

Number five from HybridPit in socal:

 

Glad I'm not in your shoes on this one. Guess you could drive it till it blows........ no matter what you better have 4 to 5 thousand set aside to get it back to at least kinda dependable despite for sure future Hybrid problems..... sorry.....

 

Considering your miles and symptoms, I’d gamble on just gasket replacement, not the full machine shop overhaul of the head. Do ensure the EGR system is thoroughly clean as well, and revisit every 50k.

I don’t see ethanol-free has, and injector cleaning being helpful. Shorter oil changes are good in general.

 

Our situations are somewhat similar (140k miles) and I can share my experience after diving into a repair. I'm a rookie as well with what I suspected to be a HG leak (very small - takes weeks to see any coolant loss) and getting misfire codes. I was getting shaking on startup (warm and cold) which would smooth out. I dove in and couldn't find any coolant in the cylinders or any signs of the leak. Nothing in the oil / no overheating. With HG on the back burner - I replaced the plugs, PCV, EGR valve and cooler, and Intake Manifold with new parts. I also installed an oil catch can. I cleaned everything that wasn't a new part including a non-invasive fuel injector cleaning since you can see the fuel injectors when everything is off.

As I said our situation is similar in that I threw some misfires initially as well when the startup would be rough.

Well guess what.... The Car has never run better after the repair. The engine shaking on startup used to occur very frequently with misfire codes infrequent. It has zero engine shaking/rattle on startup now. So if a HG is the issue and I'm not ruling that out, the repair i performed should have made no difference. 14 days since the repair and no issues - runs brand new.

In my case I justified new parts as the labor was DIY and I honestly felt it would've taken me 2-3 days of cleaning + acquiring all sorts of cleaning items (brushes and cleaner) + I'm the type to worry i do all this work and it's a stupid mechanical malfunction like a valve not working properly or I missed a blocked up intake manifold port. (Sorry that's just me). So it was worth it to me if I was going to do this repair to move those worries aside.

It's paying big dividends. I love what you did with your cleaning, my recommendation is to watch everything like a hawk and run it until the problem presents itself more clearly.

Speculation Zone (Full Disclosure: I'm probably crazy) I think my EGR valve and cooler assembly went bad as in mechanically it was not opening closing properly creating engine woes. I do not have enough information to support this so its in my speculation zone. Based on the sheer number of coolant lines going to this assembly would there be any chance a bad EGR leads to minimal coolant loss (unknown as this time).

 

Update: Head Gasket woes returned and worse than previous which was expected for the most part barring no major EGR problem.

Engine knocking/rattling on each any startup after shutoff and 30 seconds or more. (Like each traffic light). I followed the BARS Gasket Sealer instructions to a T and this resolved the issue for now. I added approx 1/2 of a bottle.

Update: My 2014 Prius v Three also has a cracked heat exchanger and I performed a bypass near the catalytic converter, then did EGR, then BARS, then did water pump, thermostat, and coolant flush. Just thought I'd mention it since most likely a high heat condition of some sort seems to have cracked the heat exchange and led to head gasket woes appearing at the same time. BTW the bypass has not thrown any codes.

Update: I replaced the stock water pump with a new Toyota water pump. I replaced the thermostat and housing. Car performed at 197.7 degrees F prior on my test course. The new water pump and thermostat now have the car at 190.4 on average and on the hottest day of the year (98 degrees). Please note: Coolant was drained at the wingnut valve and at the heat exchanger whereas if there was any BARS in the fluid it is now gone after performing its sealing duty a couple weeks before.

New speculation: High heat through clogged EGR and a less efficient water pump and thermostat with 141,000 miles may have led to the failed heat exchanger and failed HG. The vehicle was primarily used for Amazon deliveries prior to woes so received quite the torture test. The good news is I am fully operational at this point. Let's see how long the BARS seal holds up. I've slowly built up experience with the engine so I am 50/50 on the HG replacement DIY.

Side note: Never any overheating as far as a light from the car or it was missed. Expansion tank of coolant never lower than 1/4 full.


Justin, any update on where you are at with the HG? Did you take it to the dealership?

 

Not aimed at you but for the 500th time incase any potential buyers reading this DO NOT PURCHASE A GEN 3
Unless........ you like extended mental and financial pain...........

and a special no thankyou to junk toy for really terrible gen 3 engine.

 

Just forestalling the inevitable, and clogging various pricey and difficult to access components. The cabin heater core will be fun.

 

I guess the big bad egr is exonerated one more time. It IS odd but normal that cleaning things and buying new plugs buys a several week reprieve from hg symptoms. Egrs are closed normally at startups and cause roughness if they are stuck open and flowing. Other misfire sources don't quickly clear after startup in early stages. The sealer may last one to three months but the problem won't go away. Plan your strategy now and start a repair fund.

 

Nice to see my 2 Favorite People on Prius Chat posting back to back......

 

I'm not afraid to admit my mistakes lol. I'll update once and a while on this course of action and I do appreciate the forum's advice even if i go a little sideways with actions. I now look at this vehicle as a test rig.

 

RJ, I attributed the HG going away to some sort of loss and refill of coolant with the EGR swap may have shifted some debris to clog the leak for the HG. The HG leak was tiny sometimes taking a month or two to be noticeable. Just a theory because I also wondered how it ran normal for a couple weeks. Good advice, I am planning next steps once the problem returns.

 

Your experience has been repeated hundreds of times. 95% without overheating.

 

All you do is unplug the orange fused disconnect on the hv battery in the trunk. Completely safe after that.

You could do it. No gloves needed. Obviously you keep it out as you work on the car.